How to change authenticator?

I have a new phone, and I don't have access to the recovery serial number or anything. I just downloaded the authenticator app on my windows 8 phone, and it automatically gave me a (I don't know if the old one, or a new one, since it's based off my phone number which is the same) Serial and Restore code. Where on the battle.net page do i change the info. I've already tried using the random codes that are passing by on my current phone but none of them will log me in to my account.

You need to log on to battle net to remove it . Then remove it and add the new one, since it has to be registred to the account. If you can´t use the old phone - which tbh is pretty stupid not to check on before switching - then you need to call blizzard to make them do it.

"Only Jack can zip up."
The word you want to use is "have" not "of".
You may have alot of stuff in your country, but we got Lolland.